Load of using traffic to the node itself.

[Wim Van den Wyngaert]

Over here we have a lot of software that is doing decnet or IP traffic to the node itself.

I did some tests and found that all traffic is visible with "bytes transferred" in ucx show dev or mc ncl show nsp port. However, if I look in mc ncl show csm stat octets send/received, I find no increase. So, they are not registered as transferred.

1. Is the limit of 100 Mbit of my card also applicable in some way to this traffic ?

2. Is this traffic delaying normal traffic in some way (supposing that you have multiple cpu's, which I don't have) ?

Wim

[Joseph Huber_1]

Not knowing if decnet is clever enough to see the destination is local .

For IP:
check if there is a difference whether the socket is to localhost (127...) or the network node name/address ?

[Wim Van den Wyngaert]

No difference between local host and local node.

Wim

[Joseph Huber_1]

Did You just look at the number reported by UCX SH DEV/FULL ?
This shows the traffic of a socket, not which interface it is using.
A "netstat -i" gives the traffic per interface, and this would show the difference, after shifting traffic from the hardware to the LO: interface.

[Wim Van den Wyngaert]

Joseph,

Yes but I looked at the network interface level itself.

I now tried to pump data memory to memory via T2T but didn't get above 1 MB/sec on a 10Mbit card. My cpu is too slow (90% busy) to test it in dcl.

Wim

[Wim Van den Wyngaert]

1. No.

Dit a

mc dtsend
data/node=xxx/siz=1000/type=echo/stat/sec=10
and got thruput of 4.4 MByte per sec on a 10 Mbit card.

And with size 3K even 11MBytes. And 80%cpu usage.

Wim

[Robert Gezelter]

Wim,

Local traffic does not traverse the network adapter.

If you can get a throughput of 4.4MBYTE on a 10MBIT card (note capitalization), you have demonstrated it quite convincingly (the 4.4MBYTE is approximately 35 MBIT).

- Bob Gezelter, http://www.rlgsc.com

[Volker Halle]

Wim,

DECnet or TCPIP traffic between 2 (local) ports on the local node is only limited by the available CPU/memory bandwidth. You're sharing the DECnet or TCPIP stack as well as the CPU resources with real incoming/outgoing traffic, so you are 'delaying' normal traffic - a least a little bit.

Volker.